1. Field of the Invention
The present general inventive concept relates to a roller apparatus, and more particularly, to a roller apparatus to effectively ground a bushing thereof.
2. Description of the Related Art
In general, a roller apparatus has a roller main body of a cylindrical shape. The roller mail body rotates around a centering line and feeds object media in a tangential direction of the roller main body by a frictional force between the object media and the roller main body.
FIG. 1 is a schematic view illustrating a conventional roller apparatus 101. As illustrated in FIG. 1, the roller apparatus 101 has a roller 110, a frame 130, a bushing 120 and a grounding member 140. The roller 110 is frictionally supported on the bushing 120, and the frame 130 has a bushing hole 132 through which the bushing 120 passes. The frame 130 has a reinforcement part 136 extended around the bushing 120 to an axial direction P of the roller 110 and a supporting rib 134 spaced from the reinforcement part 136 and extended to the axial direction of the roller 110. The bushing 120 is inserted into the bushing hole 132 to rotatably support the roller 110.
The grounding member 140 grounds the bushing 120 by contacting the bushing 120. The grounding member 140 is connected with a grounding terminal (not shown). As the roller 110 frictionally contacts the bushing 120, the roller 110 makes friction with the bushing 120 to create static electricity between the roller 110 and the bushing 120 as the roller 110 rotates. The grounding member 140 prevents damage or malfunction of the roller apparatus 101 due to static electricity by grounding the bushing 120.
The grounding member 140 is formed of an elastic material. A first side of the member 140 is interposed between the bushing 120 and the reinforcement part 136 of the frame 130, and a second side of the member 140 is positioned to be pressed by the supporting rib 134. As the second side of the grounding member 140 is pressed to the axial direction P by the supporting rib 134, the first side of the grounding member 140 is elastically deformed to contact the bushing 120.
However, because in the conventional roller apparatus 101, the grounding member 140 is pressed by the supporting rib 134 and contacts the bushing 120 by the elastic force, a contact area with respect to the bushing 120 is small, and a contact force lowers, which requires high precision molding. If the elastic force of the grounding member 140 lowers, the supporting rib 134, the frame 130 or the bushing 120 is deformed thermally because of temperature or fatigue, and then the bushing 120 and the reinforcement 136 are separated such that the grounding member 140 may not contact the bushing 120.
Also, as the grounding member 140 is pressed to the axial direction P by the supporting rib 134, the bushing 120 is displaced toward the axial direction P, and accordingly, a position of the roller 110 may change.